Re: CPL Update

[David A. Moon <Moon@STONY-BROOK.SCRC.Symbolics.COM>]

    Date: 27 Jan 87 09:26 PST
    From: Danny Bobrow <Bobrow.pa@Xerox.COM>

    I think that [Dick's] algorithm would work the same as New Flavors if you
    used a last-visited walk....
    Dave, could you  try my variation on Gabriels algorthm against the
    new Flavors system?

I think this was the first or second modification of Gabriel's algorithm
that I tried yesterday.  The function is named Gabriel-3, but it looks
like I never finished writing Gabriel-2.  Unfortunately I had too many
other things to do today to follow up on this as I ought to have.
Looking back over my notes, I don't have any cases jotted down where
this modified Gabriel performs differently from Bobrow (Gregor's code),
except when the latter seemed to go into an infinite loop.  However, I
compared them "exhaustively" just now and found a few cases where they
produce different results.  I haven't boiled that down to a simple,
understandable case yet, though.

I do have some cases where both Gabriel-3 and Bobrow produce a different
answer from Flavors, but I haven't finished figuring out what's going on
there yet.  The difference might not be real.